Ulster have confirmed that winger Tommy Bowe will be sidelined for four months which rules him out of the Six Nations.

Bowe was stretchered off in the 77th minute of Ulster's match with the Northampton Saints on Saturday evening and there were immediate fears that the 28-year-old had suffered a severe injury. Ulster later confirmed the prognosis saying that the winger had "sustained significant lateral ligament damage to his right knee".

Bowe underwent surgery on Wednesday and now faces a lengthy spell on the sidelines. Ireland kick-off their Six Nations campaign against Wales on February 2 and their five-Test line-up concludes on March 16 against Italy. The four month prognosis from Ulster would place Bowe's return to action at some point in April.

Ulster will also feel Bowe's absence as he will miss their final two matches in the Heineken Cup pool stage and may miss the quarter-finals of the tournament if Ulster progress that far. The province are currently top of the PRO12 but face two key matches against Leinster and Munster over the next two weekends.

And the British & Irish Lions selectors will also be keeping a close eye on Bowe's recovery. He travelled with the 2009 group to South Africa and started all three of their Tests against the Boks and is considered to be in the frame for a spot on their tour to Australia in the summer.